Figure 1.

The custom biopsy instrument (SurgiPro, Minneapolis, MN) consisted of a sharpened trocar and cannula with a working shaft length of 17.5 cm and a cannula diameter of 6 mm. The combined instrument was inserted through the 11th intercostal space of the animal until the hepatic membrane was pierced, then the trocar was withdrawn, the cannula was inserted into the liver tissue, and the exterior opening of the cannula was covered as the instrument was retrieved from the animal. The negative pressure created by covering the exterior opening aspirated approximately 0.4 g of the liver tissue.